Indentation size effect on some glycine based nonlinear optical crystals

In this paper, the load dependence of Vickers microhardness has been studied on some as-grown faces of glycine complexes viz. glycine hydrofluoride (GHF), glycinium oxalate (GOX), bisglycine hydrogen chloride (BGHC) and glycine manganese chloride (GMC). The Indentation Size Effect (ISE) is examined and the load independent hardness values are determined from the theoretical models viz. Hays-Kendall approach, proportional specimen resistance (PSR) model and modified PSR model. The experimental results show that PSR model gives a poor fit of the experimental data whereas, the modified PSR model is found to be the most effective for describing experimental data and the nature of ISE.